Implementations include providing a database system that a plurality of tenant systems interact with, providing a shared database schema and a plurality of tenant database schemas, the shared database schema including a shared table, and each tenant database schema being assigned to a respective tenant and including a view into the shared table, which includes a tenant specification field, and a row visibility field, the tenant specification field indicating a tenant, to which a respective row is assigned, and the row visibility field indicating visibility of a respective row to respective tenants.